Curved escalator with vertical planar step risers and constant horizontal velocity

Abstract

The escalator has steps with vertical planar cleated risers which mesh with cleated trailing edges of the adjacent step. The step chains are selectively kinked and unkinked to provide for a constant spacing of adjacent step axles throughout the path of travel of the escalator. The steps thus display a constant horizontal velocity. The escalator can be adapted to follow a fixed center constant radius in plan helical path of travel.

What is claimed is: 
     
       1. An escalator comprising a plurality of serially disposed steps; each of said steps having a vertical planar cleated riser part, a cleated trailing edge part and a step axle; the cleats in each riser part of each step meshing with the cleats in the trailing edge part of an adjacent step; and means for moving said steps along a passenger transporting path of travel which includes a pair of landing zones, a constant slope incline zone and a pair of transition zones respectively interconnecting each landing zone with said incline zone, said means for moving being operable to move each of said steps vertically in each transition zone in a manner which does not impart horizontal acceleration to said steps while maintaining the intermeshing cleat relationship of each successive pair of steps, and said means for moving comprising lateral inner and outer step chains connected to lateral inner and outer ends of said step axles, and means for kinking said inner and outer step chains in said landing zones and straightening said inner and outer step chains in said constant slope incline zone. 
     
     
       2. The escalator of claim 1 wherein said path of travel is curvilinear as viewed in plan. 
     
     
       3. The escalator of claim 2 wherein said steps each have curved lateral inner and outer edges, when viewed in plan, which are defined by first and second constant length radii derived from a common fixed center point. 
     
     
       4. The escalator of claim 3 wherein said means for moving is operable to maintain a constant distance between adjacent step axles as measured in a horizontal plane throughout the entirety of said path of travel. 
     
     
       5. The escalator of claim 1 wherein said step chains include successive links connected to said step axles and to each other at pivot joints intermediate said step axles. 
     
     
       6. The escalator of claim 5 wherein said step axles carry inner and outer step axle rollers which travel along inner and outer step axle tracks, and said pivot joints carry cam rollers which move along inner and outer cam tracks, said inner and outer step axle tracks and said inner and outer cam tracks respectively being vertically offset from each other in said landing and transition zones, whereby said chains are kinked in said landing and transition zones and said inner and outer step axle and cam tracks being substantially coplanar to said constant slope incline zone whereby said chains are substantially straightened in said incline zone. 
     
     
       7. The escalator of claim 6 wherein said outer cam tracks and said outer step axle tracks are vertically offset in said transition zones by a distance H.sub.δ which is defined by the equation: ##EQU3## wherein: d equals the distance between the axes of one of said outer cam rollers and an adjacent outer step roller; B equals the arc length of the outer edge of a step; and   δ equals the varying angle of incline of said outer step track at any point along one of said transition zones; and wherein said inner cam tracks and said inner step tracks are vertically offset in said transition zones a distance H'δ which is defined by the equation: ##EQU4## wherein: d' equals the distance between the axes of one of said inner cam rollers and an adjacent inner step roller;     A equals the arc length of the inner edge of a step; and   δ' equals the varying angle of incline of said inner step track at any point along one of said transition zones.